4G LTE SM4 GSM Relay Controller – Smart SMS Temperature & Humidity Remote Switch for Gates & Home Appliances

Imagine opening your gate, starting a pump, or keeping your greenhouse at the perfect temperature – all from miles away, even where there’s no Wi‑Fi. The KONLEN 4G LTE SM4 GSM Relay Controller turns any compatible device into a smart, remotely controlled system using 4G, SMS, and calls. Whether you manage a farm, a workshop, a server room, or just want smarter home control, this compact aluminum box gives you reliable, always‑connected power over your equipment.

⭐ Key Benefits & Smart Features

• 4G LTE control anywhere – no Wi‑Fi needed
  Use a local 4G SIM card and control your devices from virtually any location with 4G coverage – perfect for remote gates, pumps, greenhouses, and off‑grid sites.
• Multiple control options: App, SMS, Call & Web
  Turn relays ON/OFF via the WLTE Control app, SMS commands, authorized phone calls, or a PC web browser for flexible, user‑friendly operation.
• 4 independent relay outputs (SM4)
  Control up to four devices separately – such as gate, lights, pump, and fan – from one compact controller. (SM1 version has 1 relay output.)
• Built‑in temperature & humidity automation
  Two sensor ports let you connect temperature or temperature‑humidity sensors. Set upper/lower limits to automatically switch relays for cooling, heating, humidifying, or dehumidifying.
• Perfect for gates & garage doors
  Inching mode briefly toggles the relay, simulating a button press – ideal for electric doors, gates, and garage openers.
• Scheduled & timed control
  Create schedules to turn devices on or off at specific times – great for lighting, irrigation, or energy‑saving routines.
• Real‑time monitoring & alerts
  View live temperature and humidity in the app and receive push notifications when values go above or below your preset limits.
• Up to 99 authorized call numbers
  Add trusted phone numbers that can control the device by calling – ideal for family members, staff, or maintenance teams.
• Durable aluminum alloy housing
  Robust metal enclosure with external SMA antenna for stable signal and long‑term use in technical rooms, workshops, and outdoor control boxes.
• Top‑rated & user‑friendly
  Designed for general consumers and professionals alike, with clear app interface, simple wiring diagrams, and reliable performance in demanding environments.

🚀 Real‑World Uses – From Home to Industry

Picture driving up to your property and opening the gate with a quick call. Or keeping a greenhouse at the perfect 24°C and 60% humidity without being on site. The SM4 was created for people who need reliable control where Wi‑Fi can’t reach – farmers, small business owners, IT admins, and homeowners who want peace of mind.

• Remote gates, garage doors, and barriers
• Water pumps, irrigation systems, and wells
• Greenhouses, breweries, and storage rooms
• Server rooms, routers, PBX switchboards
• Power distribution rooms and technical cabinets

With temperature and humidity sensors connected, you can feel the difference: cooler rooms when heat builds up, fresher air when humidity rises, and equipment that runs only when it truly needs to – saving energy and extending its life.

🔧 Detailed Feature Highlights

• Two control modes: 4G data mode (via WLTE Control app & web) and SMS mode (via text messages & calls).
• APN configuration: For some carriers, simply set APN once in the app to activate 4G data.
• Inching mode: Short pulse output to simulate a push button – ideal for momentary control.
• Centralized management: Manage multiple controllers in one app – perfect for multi‑site operations.
• App push notifications: Optional alerts when temperature/humidity cross your thresholds.
• Web browser control: Send ON/OFF commands from a PC (settings and notifications managed via app).
• Flexible wiring: Supports DC motors, AC bulbs/LEDs, and other loads within relay ratings; high‑power motors can be controlled via an external AC contactor.

📊 Technical Specifications